This invention relates to impact absorbing floating units movably supported through the intermediary of damper means, for example, on a chassis of a compact disk (CD) player mounted on a vehicle, and more particularly to a locking mechanism for locking the floating unit to the chassis.
Generally, a CD player for mounting on a vehicle needs to be protected from the running vibrations of the vehicle. If running vibration is applied to the sound reproduction (playback) mechanism of a CD play er, the pickup would run off the track on the CD and the sound would skip. Since the reproduction mechanism including the pickup is a precision machine, it may be damaged by an extraordinary impact.
In order to prevent such a problem, component members of the reproduction mechanism, (such as the pickup, its feed mechanism, a turntable for supporting a CD, and its driving motor in CD players for mounting on a vehicle) are mounted on a floating unit, which is supported movably to the chassis through the intermediary of damper means such as a damper spring or a rubber vibration insulator.
When vibrations are transmitted to the chassis of a CD player having such a floating unit, they would be absorbed by the damper spring or the rubber vibration insulator. Therefore, the vibrations of the traveling vehicle are not transmitted to the floating unit, thereby preventing a sound skip or an adverse effect on the reproduction mechanism.
An ordinary CD player for mounting on a vehicle has the following structure. When a CD is inserted manually into an opening provided in the chassis, it is loaded into the chassis by transfer means provided at the opening. The CD loaded into the chassis is stopped by a positioning mechanism, which is provided in the chassis at a position where the center of the CD coincides with the center of the turntable of the floating unit. When the CD stops above the turntable, clamping means come from above and from below and secure the CD to the turntable.
With CD players for mounting on a vehicle, a CD ejected from inside the chassis can be set in the opening of the chassis without being removed from the player. This is called the waiting state. Only by lightly pushing the CD set at the opening into the chassis, is the CD put into the reproducing position.
However, with a CD player for mounting on a vehicle, the floating unit bearing the turntable and the clamping mechanism is supported movably to the chassis. Under this condition, there may occur a shift in position between the floating unit and the opening, the transfer means, and the CD positioning mechanism on the chassis side.
As a result, when a CD is inserted, the opening may not coincide in position with the turntable, so that there is a possibility that the CD will be unable to be inserted or the CD will impinge on the floating unit and get damaged. Misalignment may occur between the stop position of the CD brought in by the transfer means and the position of the turntable, making clamping of the CD impossible. A similar irregularity occurs also when the CD is ejected. If there is positional misalignment between the turntable and the opening, the CD cannot be ejected. When the CD is in the waiting state, the front of the CD is located at the chassis and its rear at the floating unit. Therefore, the CD may get damaged when the floating unit moves.
Accordingly, when the CD is inserted, ejected or put in the waiting state, the floating unit must be locked at a position where the floating unit coincides with the opening of the chassis.
As a mechanism for locking the floating unit, a type of locking mechanism is used which regulates the position of the floating unit in the vertical, front-rear and left-right directions. More specifically, the regulation of the vertical direction is necessary to transfer a CD between the turntable and the clamping means. The regulation in the front-rear direction is necessary to keep constant the relative positional relationship between the positioning mechanism on the chassis side and the floating unit at all times to enable the CD to be stopped accurately at the center of the turntable. In addition, the regulation in the left-right direction is necessary to accurately position the CD and the turntable by the positioning mechanism, and to securely lock the floating unit to the chassis.
With CD players, the floating unit must be of a proper size (in terms of flat area) for mounting a CD thereon. In this case, even if only the front of the floating unit is locked, the rear side is left unlocked, causing a positional misalignment to occur between the floating unit and the chassis. Even if either the left or right side only of the floating unit is locked, the other side is not fixed, so that the floating unit is inclined left or right, thus causing a positional misalignment between the floating unit and the chassis.
Therefore, in order to lock the floating unit, it is necessary to lock the whole floating unit in a horizontal position relative to the chassis in addition to being locked in the front-rear, left-right and vertical directions. This means that the floating unit is locked at various positions around its periphery.
However, in order that the floating unit is locked in the vertical, front-rear and left-right directions and at various positions around its periphery, the locking mechanism must have many component parts. It is to be noted particularly that conventionally, special-purpose locking members have been provided for locking in the respective directions and that links disposed between a drive source (normally, a motor for insertion and ejection of a CD) for driving the locking members in different directions and the locking members have been provided in the respective directions. Therefore, many components making up the locking mechanism as necessary, thereby leading to a complexity of assembly of the locking mechanism, with the result that the production cost increases, which is economically disadvantageous.
This problem generally exists not only with CD players for mounting on a vehicle but with devices, having a floating unit supported to the chassis through the intermediary of damper means, for locking the floating unit to the chassis when necessary, some examples of which devices are other acoustic apparatuses, video apparatuses, and precision apparatuses in general, including measuring instruments required to have vibration insulating characteristics for mounting on a vehicle.